Irregular periods?

I'm fifteen and have
been getting my period for over 2 years. But even though it's evened out a bit,
it's still pretty irregular. It comes at different times every month, lasts for
different lengths, the heaviness of the flow is never predictable, and only in
the past few months have I stopped skipping a month.

I use a combination of pads tampons. I am a virgin.

Is this normal?
It can take up to 3 years for your cycle and periods to become
regular.